Field of the Invention
The invention relates to a circuit board and a manufacturing method thereof, and particularly relates to a circuit board having a photo imageable dielectric layer and a manufacturing method thereof.
Description of Related Art
Along with quick development of technology, integrated circuits (ICs) are widely applied in people's daily life. Generally, production of the ICs mainly includes three stages: manufacturing of silicon wafers, manufacturing of the ICs and packaging of the ICs. In view of a present package structure, package on package (POP) is a commonly used package type.
To be specific, a chip package is fixed on another chip package through a plurality of conductive bumps, and is electrically connected to the other chip package through the conductive bumps. In recent years, as the number of input/output (I/O) terminals required on a circuit board is gradually increased, a layout density of the conductive bumps is accordingly increased, so that demand on manufacturing precision of the conductive bumps is also enhanced. Moreover, since the chips have a certain thickness, the conductive bumps supporting between two chip packages are required to have an enough height, so as to provide an adequate space between the two chip packages for accommodating the chips. However, since the conductive bumps are required to have a higher height, side surfaces of the conductive bumps are liable to be excessively exposed to external environment to increase a risk that the conductive bumps are oxidized or eroded, which influences a yield of the chip package products.